尝试使用 ionic 中的媒体和文件进行录制时出现低质量的音频文件

我正在尝试使用媒体（https://ionicframework.com/docs/native/media）在 android 中录制音频，但录制的音频质量非常低，播放时有噪音，这是问题的链接离子论坛：https : //forum.ionicframework.com/t/low-quality-audio-file-when-trying-to-record-using-media-and-file/191952

这是我的代码：

import { Component } from '@angular/core';
import { Media, MediaObject } from '@ionic-native/media/ngx';
import { File } from '@ionic-native/file/ngx';
import { Platform } from '@ionic/angular';

@Component({
  selector: 'app-home',
  templateUrl: 'home.page.html',
  styleUrls: ['home.page.scss'],
})
export class HomePage {


  filePath: string;
  recordedAudio: MediaObject;
  recording: Boolean = false;
  constructor(
    private media: Media,
    private file: File,
    public platform: Platform
  ) { }

  startRecord() {
    if (this.platform.is('android')) {

      console.log('Android');
      console.log(this.file.externalRootDirectory);
      this.filePath = this.file.externalRootDirectory + 'my_file.3gp';
      console.log(this.filePath)
      this.file.createFile(this.file.externalRootDirectory, 'my_file.3gp', true).then(() => {
        this.recordedAudio = this.media.create(this.file.externalRootDirectory.replace(/^file:\/\//, '') + 'my_file.3gp');
        this.recordedAudio.startRecord();
        window.setTimeout(() => this.recordedAudio.stopRecord(), 50000);
      });
    }
    this.recording = true;
  }

  stopRecord() {
    if (this.platform.is('android')) {
      this.recordedAudio.stopRecord();
      this.recordedAudio.release();
    }

  }

  playSelectedTrack() {
    // use AudioProvider to control selected track 
    if (this.platform.is('android')) {
      this.recordedAudio.play();
    }
  }

  pauseSelectedTrack() {
    // use AudioProvider to control selected track 
    if (this.platform.is('android')) {
      this.recordedAudio.pause();
    }
  }
}